An efficient straight through medium-heavy plate production line of double rack and double shearing line and a production method are provided. The medium-heavy plate production line comprises: a main rolling line, at least two parallel shearing lines, and straightening stacking lines that are each configured parallel outside each of the shearing lines, the main rolling line comprises: a heating furnace, a high pressure water descaling machine, a fixed width press, a stand roller, a four-roll roughing mill, an intermediate cooling device, a four-roll finishing mill, an ACC accelerated cooling device, a hot straightening machine, a 1# labeling device and a hot segmenting shear are arranged in order, and a 1# cooling bed, a 1# inspection stand, a 2# cooling bed and a 2# inspection stand are arranged at two sides of the steel rolling and delivery rolling way; a plate turnover machine; and a traverse stand.

A plant and process for the continuous production of hot-rolled steel strips with a minimum thickness of 0.3 mm is disclosed which includes a continuous casting device of thin or medium slabs with a thickness between 40 and 150 mm and a maximum width of at least 2100 mm followed by a roughing mill, a first induction furnace, a water descaler, a second induction furnace, a finishing mill, a cooling station, a cutting station and a winding station. A system for feeding a protective atmosphere containing ≤3% vol. oxygen is provided from the inlet of the second induction furnace to at least the third stand of the finishing mill. Between the continuous casting device and the roughing mill, an initial thermal conditioning and descaling section is provided having in sequence an induction edge heater, an induction heater for the rest of the slab surface and a water descaler.

A cold-rolled steel strip manufacturing facility includes: a joining device configured to join a trailing end of a preceding steel strip and a leading end of a following steel strip to form a joined steel strip; a looper configured to store the joined steel strip; a heating device configured to heat a joint portion between the preceding steel strip and the following steel strip over an entire width direction; and a cold rolling mill configured to cold-roll the joined steel strip for which the joint portion was heated by the heating device, wherein the heating device is switchable between an output state and a non-output state, and during a period in which the joint portion passes through the heating device, is switched to the output state.

An inductor intended to heat a flat product by transverse flow induction, with an upper face and a lower face, comprising coils having surfaces which extend over planes, are parallel to each other, and with a thickness in a direction perpendicular to the planes; and a central space between the coils. Wherein at least two coils are disposed on a first side of the central space and at least two coils are disposed on a second side of the central space, wherein on the same side of the central space, the coil closest to the face is spaced apart therefrom by a first distance and the other coils are disposed at a distance from the face that is at least equal to the first distance plus the thickness of the coils between them and the face of the product, and wherein the surfaces of the coils at least partially overlap.

In a decision control device of a control system, a predetermined pass schedule is decided by adjusting the rolling force per unit width at a last stand of a hot finishing tandem rolling mill to cause the edge profile on the outlet side of the last stand to fall within an allowable range based on the relationship between a strip crown and the edge profile on the outlet side of the last stand with respect to the rolling force per unit width and a strip shape control parameter, obtained regarding the last stand, and adjusting the strip shape control parameter of the last stand to cause the strip shape on the outlet side of the last stand to fall within an allowable range and cause the strip crown to become a predetermined value or smaller.

An apparatus line for manufacturing seamless steel pipes and tubes includes: a heating apparatus for heating a steel raw material; a piercing apparatus for piercing the heated steel raw material thus forming a hollow material; and a rolling apparatus for applying working to the hollow material to form a seamless steel pipe having a predetermined shape. A cooling apparatus is arranged on an exit side of the rolling apparatus. A heated steel raw material is worked by the rolling apparatus after being pierced by the piercing apparatus, and thereafter, using a surface temperature of a hollow piece before being cooled by the cooling apparatus as a cooling start temperature, the hollow piece is cooled to a cooling stop temperature differing by 50° C. or more from the cooling start temperature and being equal to or above 600° C. at an average cooling speed of 1.0° C./s or more in terms of an outer surface temperature.

There is provided a meandering control device for a rolling line capable of setting temperature of a material to be rolled so as to suppress meandering of the material to be rolled. The meandering control includes a tail end roll force calculation unit that calculates a predictive value of roll force when entry side tension is not applied, an allowable meandering amount roll force calculation unit that calculates a reference value of the roll force applied to the material to be rolled when a meandering amount of the material to be rolled is an allowable amount, and a temperature rise amount calculation unit that calculates a temperature rise amount of the material to be rolled, based on a difference between the predictive value of the roll force and the reference value of the roll force.

A forge and method of forging is provided. The forge converts an asymmetric railroad rail to a symmetric railroad rail through a combination of vertical and horizontal forging operations. The rail is linearly translated to heating and forging stations on a roller table. The asymmetric to symmetric conversion can be completed without the need for reorienting the rail except along a single translational axis.

Manufacturing a cold-rolled steel plate by smelting a steel slab having the chemical composition containing on the basis of percent by mass, C from 0.03 to 0.12%, Si from 0 to 1.0%, Mn from 0.2 to 0.8%, P at 0.03% or less, S at 0.03% or less, Ti from 0.04 to 0.3%, and Al at 0.05% or less, with a residue being formed of Fe and unavoidable impurities, the chemical composition satisfying 5*C%-Si %+Mn %−1.5 *Al %<1, and an average diameter of particles of a Ti-based carbide as a precipitate is from 20 to 100 nm; heating the slab to 1200° C. or more and hot rolling, forming a hot-rolled steel plate; winding the hot-rolled steel plate from 500 to 700° C. to form a hot-rolled coil; and cold rolling or annealing and cold rolling the coil obtaining cross-sectional hardness from 200 to 400 HV.

A high strength interstitial free low density steel and method for producing the steel.